Safety device for elevator cage and shaft doors



p 1930- F. A. BOED'TCHER 1,752,476

SAFETY DEVICE FOR ELEVATOR CAGE AND SHAFT DOORS Filed Feb. 15, 1928 2 Sheets-Sheet 1 INVENTOR. 50024 flaeofcfier April 1, 1930. F. A. BOEDTCHER SAFETY DEVICE FOR ELEVATOR CAGE AND SHAFT DCSORS Filed Feb. 15, 1928 2 Sheets-Sheet 2 il 474//////2 I| 1 \\\\\\\\\\\\il ATTO NEYS.

Patented Apr. 1, 1930 I UNITED STATES PATENT OFFICE FRANZ A. BOEDTCHER, OF BEBGEN'FIELD, NEW JERSEY, ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY SAFETY DEVICE FOR ELEVATOR CAGE AND SHAFT DOORS Application filed February 15, 1928.

This invention relates to elevator installations and more particularly to a safety de vice adapted to be associated with elevator cage and shaft doors and gates.

It is not unusual under present practice to make such doors or gates quite heavy and to operate them by pneumatic or other mechanical devices which function to open and close the doors. WVhen heavy doors are employed and operated automatically, the door operating mechanism must necessarily be powerful in order to effect the opening and closing of the door within such relatively short periods as efiicient elevator operation requires.

It is not an unusual occurrence for persons to be caught between the door casing and the door during the closing operation of the latter and when the doors are heavy and positively operated, serious injury is very apt to result. This hazard incident to elevator operation has long been recognized, but no satisfactory and practical expedient has been produced for solving the problem involved.

The object of the present invention is to provide simple and efiicient mechanism which will safeguard persons, entering or leaving an elevator cage, against injury by the door of the cage or shaft.

Speaking generally, the invention consists in associating with the edge of the door an operating member with which is associated brake mechanism. The brake operating member is so positioned that when any part of a person is in a position to be struck by the door during its closing movement, said person will be engaged by the brake operating element, whereby continued movement of the door will effect the operation of the brake operating element to brake the door against further closing movement. The braking mechanism which is associated with and opepated by the brake operating member may be of such character as to produce a frictional or positive braking operation Without departing from this invention and the structure may be so constituted as to brake the door at both its top and bottom, although ordinarily it is found that braking of the door at either its top or bottom will thoroughly safeguard a Serial No. 254,335.

person who might otherwise be caught and injured.

In practically carrying out the invention, the brake operating mechanism may conveniently be in the form of a bar extending vertically of the door and at the free edge of the latter.- This bar is mounted for movement in a direction parallel to the normal direction of movement of the door and is so mounted that attempted movement in such direction will be translated into vertical movement of the bar. Either the upper or lower end of the bar is provided with a braking device which may, in practice, be in the form of a friction shoe or a detent, so that when the bar engages the person during closing movement of the door, the bar will be vertically shifted either to engage the frictional shoe with a stationary part of the building or elevator or to engage the detent with rack or other analogous fixedly mounted part. The present invention may be used in conjunction with either sliding or hinged doors, although primarily intended for use on the former type.

Features of the invention, other than those 7 adverted to, will be apparent from the hereinafter detailed description and claims, when read in conjunction with the accompanying drawings.

The accompanying drawings illustrate different practical embodiments of the invention, but the constructions therein shown are to be understood as illustrative, only, and

not as defining the limitsof the invention.

Figure 1 showsa doorway. with an associated door mounted for sliding movement and having associated therewith safety means embodying the present invention.

Figure 2 is an enlarged detail view showing a portion of the structure of Figure 1 in different operative positions.

Figure 3 is a fragmental perspective detail of parts illustrated in Figures 1 and 2.

Figure 4 is a perspective View illustrating a modified form of construction.

In Figure '1, I have shown conventional parts in a Very diagrammatic manner as particular door shaft or car construction is not material to the present invention, the same being adapted for cooperation with any conventional installation. A single door is shown in Figure 1, but the invention may be associated ith sectional doors common in elevator installations.

In the drawings, 1 shows the doorway of the shaft or cage, and 2 the door shown as mounted to move edgewise on trolleys 3 supported on a suitable track a. The door illustrated is of the mechanically operated type, the operating mechanism being illustratively shown as embodying a toggle 5.

The door 2, as shown in Figures 1 to 8, is provided atits forward edge with a bar 6 which extends vertically of the door and projects slightly beyond the forward edge 2 of the latter. This bar is connected to the door by links 7, one end of each link being pivoted to the door and the other end being pivoted to the bar.

One or more of the links is provided with a tail piece 8 and a spring 9 bears on the tail piece and is associated with an adjusting screw 10 threaded through a bracket 11 on the door. The screw 10 is so adjusted as to regulate the tension of the spring in a manner to normally counterbalance the weight of the bar 6 and force the tail piece 8 down against a limiting stop 12. Vhen the parts are in this position, they appear as shown in Figure 1, wherein it will be noted that all the links are inclined with respect to the horizontal.

The lower end of the bar 6 is provided with a short lateral extension 13 to the under side of which is fixedlv secured a brake shoe 14 of friction material. The arrangement is such that when the parts are as shown in Figure 1, the brake shoe will be lifted clear of the floor. If a person happens to be in the path of the door during its closing movement, such person will be engaged by the bar 6 and the tendency of the door to continue such movement will cause the bar to press against the person. Such pressure will meet the resistance of the person and movement of the bar with the door will be arrested with the result that the bar will be forced in a. retrograde direction. By virtue of the inclined position of the links, such retrograde movement of the bar will be translated into a downward movement thereof with the result that the brake shoe 1 1 will be forced with considerable pressure against the floor and will set up, with the floor, a braking action which will serve to arrest the movement of the door. Any tendency of the door to lift during this operation is in practice offset or counteracted by particular hanger construction or by a bumper 15 which is adapted to engage with the underside of the track 4.

In practice the pressure on the bar 6 neces sary to bring about the braking action is negligible and the door is thus ethciently and easily stopped without doing injury to the person who may be in its path. As soon as the person removes himself from the path of the door, the braking action discontinues and the spring 9 again lifts the bar so that the door may continue its closing movement.

In the construction which I have described, the brake shoe is mounted at the bottom of the bar and cooperates with the floor, but it may, if desired, be mounted at the top of the bar and cooperate with the under side of the track or any other suitable fixed sur face. Moreover, the invention is capable of duplication to permit simultaneous braking at both the top and'bottom'of the door.

Referring now to the structure of Figure i, the door 2 is shown as provided with two braking bars (3 and (3 The braking bar (5 is practically identical with the structure shown in Figure 1, except that instead of employing a brake shoe at its bottom, the bar is formed with a tooth or dctent 1 L" adapted to cooperate with a rack 16 set into the floor, so that when the bar 6 is engaged, it

'ill be depressed to positively stop the door by engagement of the detent with a rack. The bar t?" is provided at its top with a detent 14" adapted to engage with a rack 17 mount ed on the track i or otherwise iixed in position. It will be note however, that the links 7" incline upwardly instead of downwardly as is the case with the links 7, and as a insult the pressure against the bar 6 will effect upward movement of the rack, instead of downward in 'veinent thereof. One or more of the links 7 and '4'" are countcrlnilanccd by spring and adjusting screw arrangement corresponding to the arrangement shown in Fig ure 1, so as to i'lorinally counterbalance the respective bars and maintain them free from their respective racks, but if a person is en gaged with the bars by a closing of the door, said bars will simultaneously move vertically to engage their respective racks and positively stop the door.

I wish it understood that instead of employing detents and racks with the twin bars shown in Fig. '11, brake shoes may he used instead and that instead of using a brake shoe on the single bar of Figures 1 and 2, a detent and rack arrangement may be employed. The several struct ral details which I have described are to be understood as interchangeable in the various structures.

I do not, moreover, limit the present invention to the particular shape of braking bars which are shown in the drawings as these bars may be of any shape, may be either positioned laterally of the faces of the door or they may be set into slots in the edge of the door, or otherwise associated with the door to mount the bar or bars on the door in a manner to translate horizontal movement into a vertical braking action with a relatively stationary part of the installation. The links and bars constitute, broadly speaking, a sort of toggle arrangement and this arrangement has been ill;

found in practice to give highly satisfactory results through the employment of a relatively simple and economical structure.

The present invention is therefore to be understood as not limited to details of construction, but is to be construed as fully commensurate with the appended claims.

I wish to particularly point out that the safety devices of this invention do not in anywise interfere with the operation of the door except at such times as they are functioning to protect a person in the path of the door. The parts are rugged, will not get out of order and involve practically no maintenance costs. I

The invention has been shown in the drawings as embodied in horizontal sliding door construction, but I wish it understood that it may be applied to vertically sliding doors or to hinged or folding doors either vertically or horizontally operated. Furthermore, it may be associated with either single or multiple doors as may be desired.

Moreover, I have described the invention as particularly adapted to function as a safety device for preventing injury to persons entering and leaving the elevator cage.

It will of course be understood in this connection that the invention will not only serve as a positive safeguard for persons, but will also protect trucks, baby carriages, or any other inanimate object that may constitute an obstruction to the closing of the door, from property damage when engaged by the door. In other words, if a door or doors embodying the present invention strike an obstruction, the door will be automatically braked so that no damage is done and no injury will result.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is 1. In an assembly of the character described, a door, an actuating bar extending vertically along the free edge of the door, a link connection between the door and the bar to provide for relative movement between the bar and door, means for normally main taining the links of such connection in inclined relation, and a braking device associated with one end of the bar, whereby, when the door moves into a position to strike an obstruction in its path, the bar will be engaged and swung on its link connection to partake of vertical movement for the purpose of bringing the braking device into engagement with a suitable stationary part to brake the door against further closing movement.

2. In an assembly of the character described, a door, an actuating bar extending vertically along the forward edge of the door, means for mounting the bar for movement in the direction of the door when it strikes an obstacle in the path of the door and for converting such movement into longitudinal movement of the bar, and braking means associated with the bar adapted to be brought into engagement with a suitable stationary part when-the bar is moved relative to the door upon engagement with an obstruction for the purpose of braking the door against further closing movement.

3. In an assembly of the character described, a door, an actuating bar extending vertically along the free edge of the door, a plurality of links, one end of each of which links is secured to the bar while the other end of each link is secured to the door, all of said links being arranged in parallel relation, means for normally yieldably maintaining the opposite ends of the bar free from engagement with any stationary part, and braking means associated with one end of the bar, whereby when the bar engages an obstruction, said bar is forced toward the door and said movement is translated into longitudinal movement of the bar for the purpose of forcing the braking means into engagement with a suitable relatively stationary part to brake the door against further closing movement.

l. In an assembly of the character described, two actuating bars extending in parallel relation vertically along the free edge of the door, means for yieldably supporting said bars for movement in a direction counter to the direction of closing movement of the door and for translating such movement into vertical movement of the bars, each in an opposite direction to the movement of the other, and braking means associated with the upper end of one bar and the lower end of the other bar and adapted when the bars meet an obstruction with consequent longitudinal movement, the braking means will be forced into engagement with relatively stationary parts for the purpose of braking the door against further closing movement.

In testimony whereof I have signed the foregoing specification.

FRANZ A. BOEDTCHER. 

